How does the brain learn grammar?

We begin to learn our native language as babies. This happens automatically. We are not aware of it. Our brain has to accomplish a great deal when learning, however. When we learn grammar, for example, it has a lot of work to do. Every day it hears new things. It receives new stimuli constantly. The brain can't process every stimulus individually, however. It has to act economically. Therefore, it orients itself toward regularity. The brain remembers what it hears often. It registers how often a specific thing occurs. Then it makes a grammatical rule out of these examples. Children know whether a sentence is correct or not. However, they don't know why that is. Their brain knows the rules without having learned them. Adults learn languages differently. They already know the structures of their native language. These build the basis for the new grammatical rules. But in order to learn, adults need teaching. When the brain learns grammar, it has a fixed system. This can be seen with nouns and verbs, for example. They are stored in different regions of the brain. Different areas of the brain are active when processing them. Simple rules are also learned differently than complex rules. With complex rules, more areas of the brain work together. How exactly the brain learns grammar hasn't been researched yet. However, we know that it can theoretically learn every grammar rule…

______ is among the languages that dominate the book market.
Great works in world literature were written by ______ authors.
Thus many books are translated from ______.
______s also enjoy reading new texts so translators always have a lot to do.
______ is the native language of about 160 million people.
Additionally, many people in other Slavic countries speak ______.
With that, ______ is the most widespread language in Europe.
Approximately 280 million people speak ______ worldwide.

As an Eastern Slavic language, ______ is related to Ukrainian and Belarusian.
______ grammar is structured very systematically.
That is an advantage for people who like to think analytically and logically.
______ is absolutely worth learning!
______ is an important language in science, art and technology.
And wouldn't it be nice to be able to read famous ______ literary works in their original form?